1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Renesas R-Car E-FUSE/OTP Driver
4 *
5 * Copyright (C) 2024 Glider bv
6 */
7
8 #include <linux/device.h>
9 #include <linux/export.h>
10 #include <linux/io.h>
11 #include <linux/nvmem-provider.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_runtime.h>
14 #include <linux/property.h>
15
16 struct rcar_fuse {
17 struct nvmem_keepout keepouts[2];
18 struct nvmem_device *nvmem;
19 struct device *dev;
20 void __iomem *base;
21 };
22
23 struct rcar_fuse_data {
24 unsigned int bank; /* 0: PFC + E-FUSE, 1: OPT_MEM + E-FUSE */
25 unsigned int start; /* inclusive */
26 unsigned int end; /* exclusive */
27 };
28
rcar_fuse_reg_read(void * priv,unsigned int offset,void * val,size_t bytes)29 static int rcar_fuse_reg_read(void *priv, unsigned int offset, void *val,
30 size_t bytes)
31 {
32 struct rcar_fuse *fuse = priv;
33 int ret;
34
35 ret = pm_runtime_resume_and_get(fuse->dev);
36 if (ret < 0)
37 return ret;
38
39 __ioread32_copy(val, fuse->base + offset, bytes / 4);
40
41 pm_runtime_put(fuse->dev);
42
43 return 0;
44 }
45
rcar_fuse_probe(struct platform_device * pdev)46 static int rcar_fuse_probe(struct platform_device *pdev)
47 {
48 struct device *dev = &pdev->dev;
49 const struct rcar_fuse_data *data = device_get_match_data(dev);
50 struct nvmem_config config = {
51 .dev = dev,
52 .name = "rcar-fuse",
53 .id = NVMEM_DEVID_NONE,
54 .owner = THIS_MODULE,
55 .type = NVMEM_TYPE_OTP,
56 .read_only = true,
57 .root_only = true,
58 .reg_read = rcar_fuse_reg_read,
59 .word_size = 4,
60 .stride = 4,
61 };
62 struct rcar_fuse *fuse;
63 struct resource *res;
64 int ret;
65
66 ret = devm_pm_runtime_enable(dev);
67 if (ret < 0)
68 return ret;
69
70 fuse = devm_kzalloc(dev, sizeof(*fuse), GFP_KERNEL);
71 if (!fuse)
72 return -ENOMEM;
73
74 fuse->base = devm_platform_get_and_ioremap_resource(pdev, data->bank,
75 &res);
76 if (IS_ERR(fuse->base))
77 return PTR_ERR(fuse->base);
78
79 fuse->dev = dev;
80 fuse->keepouts[0].start = 0;
81 fuse->keepouts[0].end = data->start;
82 fuse->keepouts[1].start = data->end;
83 fuse->keepouts[1].end = resource_size(res);
84
85 config.keepout = fuse->keepouts;
86 config.nkeepout = ARRAY_SIZE(fuse->keepouts);
87 config.size = resource_size(res);
88 config.priv = fuse;
89
90 fuse->nvmem = devm_nvmem_register(dev, &config);
91 if (IS_ERR(fuse->nvmem))
92 return dev_err_probe(dev, PTR_ERR(fuse->nvmem),
93 "Failed to register NVMEM device\n");
94
95 return 0;
96 }
97
98 static const struct rcar_fuse_data rcar_fuse_v3u = {
99 .bank = 0,
100 .start = 0x0c0,
101 .end = 0x0e8,
102 };
103
104 static const struct rcar_fuse_data rcar_fuse_s4 = {
105 .bank = 0,
106 .start = 0x0c0,
107 .end = 0x14c,
108 };
109
110 static const struct rcar_fuse_data rcar_fuse_v4h = {
111 .bank = 1,
112 .start = 0x100,
113 .end = 0x1a0,
114 };
115
116 static const struct rcar_fuse_data rcar_fuse_v4m = {
117 .bank = 1,
118 .start = 0x100,
119 .end = 0x110,
120 };
121
122 static const struct of_device_id rcar_fuse_match[] = {
123 { .compatible = "renesas,r8a779a0-efuse", .data = &rcar_fuse_v3u },
124 { .compatible = "renesas,r8a779f0-efuse", .data = &rcar_fuse_s4 },
125 { .compatible = "renesas,r8a779g0-otp", .data = &rcar_fuse_v4h },
126 { .compatible = "renesas,r8a779h0-otp", .data = &rcar_fuse_v4m },
127 { /* sentinel */ }
128 };
129 MODULE_DEVICE_TABLE(of, rcar_fuse_match);
130
131 static struct platform_driver rcar_fuse_driver = {
132 .probe = rcar_fuse_probe,
133 .driver = {
134 .name = "rcar_fuse",
135 .of_match_table = rcar_fuse_match,
136 },
137 };
138 module_platform_driver(rcar_fuse_driver);
139
140 MODULE_DESCRIPTION("Renesas R-Car E-FUSE/OTP driver");
141 MODULE_LICENSE("GPL");
142 MODULE_AUTHOR("Geert Uytterhoeven");
143